Alexandre Baralle's research while affiliated with Institut de Science des Matériaux de Mulhouse and other places

... Another drawback of visible light photopolymerization is that visible ligh photons are less energetic than UV photons, so more reactive photo-initiating system have to be developed in order to overcome this lower energy. In the search for highly reactive photo-initiating systems, numerous structures have been examined as potentia candidates capable of addressing the reactivity issue and carbazoles [34][35][36][37][38][39][40][41][42][43][44][45][46][47], dihydroan thraquinones [48], camphorquinone [49,50], chalcones [9,[51][52][53][54][55][56][57][58][59][60][61][62][63], naphthalimides [64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82] benzophenones [83][84][85][86][87][88][89][90], silyl glyoximides [91], phenothiazines [92][93][94][95][96][97][98][99][100][101][102][103], thioxanthone [28,[104][105][106][107][108][109][110][111][112][113][114][115][116], curcumin [117][118][119][120], pyrenes [121][122][123][124][125][126][127][128][129], iodonium salts [64,[130][131][132][133][134][135][136], push pull dyes [137][138][139], copper complexes [140][141][142][143], iron complexes [144,145] zinc complexe [146] iridium complexes [147,148] and N-heterocyclic carbene boranes [29] can be cited among the most extensively studied structures of the past decade. Beyond the simple se lection of the chromophore, the way how to generate initiating species is important. ...

... Cyanine dyes are widely used as PDT agents with absorption peaks in NIR range [81]. Heptamethine cyanine dyes could also act as photocatalysts of several reactions and accumulate specifically in mitochondria [82]. Utilizing those properties of cyanine dyes, Li et al. synthesized a prodrug 29 of cisplatin with two moieties of cyanine photoactive ligand based on IR-780 dye ( Figure 16) [67]. ...

... ESR-spin trapping spectrum of the CQ/N-methylglycine ethyl ester/HEA system after irradiation (Fig. 8) shows that there produce two kinds of free radicals, one of which is the methylene free radical produced by N-methylglycine ethyl ester (hyperfine coupling constants of the -CH•-/PBN adducts are a N = 15.3 G; a H = 1.9 G, in [28][29][30]), and the other of which might be the radicals from HEA. From the above Table 1, we found that phenylalanine methyl ester didn't have the ability to initiate polymerization, but glycine methyl ester did. ...

... A photoinduced electron transfer from the photosensitizer towards the onium salts is the key step to generating initiating radicals. However, Type II photoinitiators are also combined with hydrogen donors, leading to the formation of a ketyl radical with hydrogen abstraction and an additional radical issued from the hydrogen donor (See Scheme 1) [105,110,[169][170][171][172][173][174]. Considering that Type II photoinitiators are bimolecular photoinitiators, the introduction of a sacrificial amine can contribute to regenerating the photosensitizer in its initial redox state during the polymerization process so that this latter can be introduced in a catalytic amount. ...

... It's well known that Yagci [13][14][15] and co-workers introduced sulfhydryl, fluorene carboxylic acid and acetic acid derivatives into benzene structure of UV PI thioxanthones to increase their photoactivity in the blue region for both free radical and cationic photopolymerization [16]. Moreover, Lalevée and Dumur developed a mass of charge transfer complexes (CTCs) [17][18][19][20][21] using aromatic donors and iodonium salts as acceptors. These CTCs showed broad absorption spectra extending to blue or green light region and exhibited high initiating efficiency for free radical promoted cationic photopolymerization (FRPCP) [22]. ...

... Such CTCs exhibit extremely excellent initiating capabilities, particularly for the photopolymerization of extremely deep samples (9 cm using a LED@405 nm at 230 mW cm − 2 ) [18]. However, the CTCs can generate free-radical cations at room temperature and typically decrease the thermal stability of photosensitive systems [27]. ...

... The curing zone is the area from the exit of the nozzle to the beginning of the solidified element. Due to the exothermic reaction taking place during the curing process, this area can be easily observed with the Thermal View camera which has also been demonstrated by Garra et al. (Garra et al., 2018). The length of the curing zone depends on both UV-light intensity and feedrate. ...

... Despite this, trifluoroborates span a vast range of oxidation potentials (1.1 V to 1.83 V, benzyl vs. primary or aryl) providing a degree of unpredictability with substrate specificity. [38] To address this, boronate precursors with a lower oxidation potential, achievable by increasing electron density at boron, are required. ...

... This 'additional' step often appears to be intrinsic in many cases, as ammonia's high boiling point relative to its heavier congeners is indicative of the formation of strong hydrogen bonding, which also results in a high heat of vaporization (23.35 kJ/mol)(Barron, 2020). ...

... Activation of the alcohol was accomplished by preparing the thiocarbonate, followed by heating with HSnBu 3 and AIBN. This sequence is traditionally used for deoxygenation of secondary alkyl hydroxyl groups with few published examples of benzylic alcohol deoxygenation [50,51]. At this point we confirmed the C9/C7 anti-configuration (pironetin numbering) by 13 C chemical shift analysis of the acetonide of the deoxygenated intermediate derived from 26. ...